1. Field of the Invention
The invention relates generally to the field of preparing multimedia data for transmission. More particularly, the invention relates to using digital video encoding techniques to provide efficient use of channel bandwidth and provide updates to video images.
2. Discussion of the Related Art
The acceptance of digital video compression standards, such as those included in the Motion Picture Expert Group (MPEG) standards (including MPEG-2), combined with high-bandwidth communication infrastructure have positioned cable television users with many service selections including video-on-demand, multi-party interactive video games, and video teleconferencing. Cost-effective versions of these services, as well as Internet access using cable television, require improved video composition and display techniques to assure that user expectations regarding clarity of image and speed of response are met.
Previous solutions for preparing multimedia data using digital video data compression include those described by U.S. Pat. No. 5,623,308, issued to Civanlar et al. on Apr. 22, 1997 and U.S. Pat. No. 5,691,768, issued to Civanlar et al. on Nov. 25, 1997. According to these solutions, an encoder produces a single coded and compressed output stream in slices of macroblocks of pixel data. The output bitstream is demultiplexed into separate resolution bitstreams using identifier for each slice and for the first macroblock of each slice. The decoder processes the slices within the bitstreams of different resolutions received from plural sources using the identifiers for each slice to produce a single composite bitstream of successive slices.
This technique is well adapted to provide compressed bitstreams for full-screen motion videos. However, the technique does not provide additional compression for partial screen motion, or partial screen updates. Examples of partial screen motion include partial screen animation, scrolling an image that is larger than the viewing area to view obscured areas, and picture-in-picture motion. Partial screen updates include variable input fields, user selection graphics, and segmented images. What is needed is a system and method that provides additional compression and image clarity advantages for partial screen motion and partial screen updates.
A primary goal of various embodiments of the invention is to overcome problems in previous solutions for preparing data and transmitting data for updating video images that have less than full screen motion. The previous data preparation and transmission solutions provide encoding and decoding using frame formats and address full-screen motion video. These solutions do not adequately address channel throughput and set-top box processing limitations by using software efficiencies that can be realized by updating and transmitting only portions of the frame data for updating video images that have less than full screen motion.
In accordance with these goals, there is a particular need for pre-rendering, encoding and otherwise formatting data for updating video images that have less than full screen motion. Thus, it is rendered possible to simultaneously satisfy the above-discussed requirements of preparing and transmitting the video data for less than full screen motion, which, in the case of the prior art, are not simultaneously satisfied.
A first aspect of the invention is implemented in an embodiment that is based on a method for preparing multimedia data using digital video data compression. The method includes pre-rendering a bitmap to create a compressed form of the bitmap, the bitmap including content of a series of video images of the multimedia data, the video images having a full-sized area; and determining a viewable area of the video images to be displayed, the viewable area of the video images is smaller than the full-sized area.
A second aspect of the invention is implemented in an embodiment that is based on a method for transmitting multimedia data using digital video data compression. The method includes the steps of the first aspect and adds the step of transmitting frames of data representing portions of the video images to processing equipment, the processing equipment is connected to at least one display.
A third aspect of the invention is implemented in an embodiment that is based on a system for transmitting multimedia data using digital video compression. The system includes a crawler adapted to update references to media assets disposed in markup language files, and provide content including markup language files to a renderer; the renderer adapted to render the content into fat macroblock formatted data sets; a rendered cache adapted to store files of the fat macroblock formatted data sets; a server adapted to submit requests for data to a browser, and deliver encoded multimedia data streams to a cable network; the browser is adapted to respond to requests from the server by collecting data from the crawler and the rendered cache, and submit the collected data to the server.
A fourth aspect of the invention is implemented in an embodiment that is based on a method of distributing Internet data to digital cable devices. The method includes pulling initial content from the Internet; pre-rendering a bitmap corresponding to the initial content to create a compressed form of the bitmap, the bitmap corresponding to a series of video images of the multimedia data, the video images having a full-sized area; determining a viewable area of the video images to be displayed, the viewable area of the video images is smaller than the full-size area; and transmitting frames of data representing portions of the video images to digital cable processing equipment, the digital cable processing equipment is connected to displays for more than one user.
A fifth aspect of the invention is implemented in an embodiment that is based on a method of using a television channel to provide Internet access. The method includes pulling initial content from the Internet; pre-rendering a bitmap corresponding to the initial content to create a compressed form of the bitmap, the bitmap corresponding to a series of video images of the multimedia data, the video images having a full-sized area; determining a viewable area of the video images to be displayed, the viewable area of the video images is smaller than the full-size area; storing multimedia data elements including the bitmap in a server system; multiplexing the multimedia data elements into frames of data; transmitting frames of data from the server system to a cable network; and transmitting streams of data representing portions of the video images in a television channel to digital cable processing equipment, the digital cable processing equipment is connected to at least one display for a user.
A sixth aspect of the invention is implemented in an embodiment that is based on a method of providing a picture-in-picture display. The method includes pre-rendering a bitmap to create a compressed form of the bitmap, the bitmap including content of a series of video images of the multimedia data, the video images having a full-sized area; determining a viewable area of the video images to be displayed, the viewable area of the video images is smaller than the full-sized area; rendering the content of the video image; and updating macroblocks for a portion of the viewable area corresponding to a picture-in-picture display, the updated macroblocks including one or more of predicted frames and bi-directional frames including images corresponding to full motion for the picture-in-picture display.